Opcodes · introspection · enabled

OP_TXINPUTCOUNT (0xc3)

Pushes the number of inputs in the transaction.

Verified
Stack in → out
∅ → count
Since
May 2022: native introspection and 64-bit math
Cost
Base instruction cost 100 plus the byte length of the pushed result (2025 VM limits).
Bitcoin status
Not in Bitcoin (BTC)BTC has no native introspection opcodes. In Tapscript (BIP-342) this byte is an OP_SUCCESSx code reserved for future soft forks.

Example

OP_TXINPUTCOUNT OP_1 OP_NUMEQUAL

Step through it opcode by opcode in Bitauth IDE, the in-browser BCH VM debugger.

Sources

  1. CHIP-2021-02 Native Introspection Opcodes
  2. Libauth BCH_2023_05 opcodes (bch-2023-opcodes.ts)
  3. CHIP-2021-05 VM Limits: Targeted Virtual Machine Limits